JPH0526241U - Pallet clamp device - Google Patents

Abstract

(57) [Summary] [Purpose] A locking device that prevents the pallet from dropping or rising even if the hydraulic pressure for holding the pallet is reduced by using the standard pallet without any special processing on the pallet. Is what you are trying to get. [Structure] The piston 7 with a ball type collet that holds the pull stud 5 on the lower surface of the pallet 1 is spring 20 of the piston 18 of the lock cylinder mechanism B when the hydraulic pressure drops due to an abnormality or the like.
The lock pin 17 is engaged with the pallet-holding collet-attaching piston 7 by the displacement due to, and the holding of the pull stud 5 is continued.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a pallet clamp device, and can be used as a clamp device for a table of machine tools such as a work setup station, a cleaning station, and a machining center.

[0002]

[Prior Art]

 For example, when performing setup work by inclining the pallet at the work setup station of the processing system, the hydraulic pressure is cut off when the power is turned off, the pallet is in an unclamped state, and the operator may drop it. To do. In order to prevent accidents for workers due to such a drop, for example, as shown in Japanese Utility Model Laid-Open No. Sho 63-57036, by engaging the locking pin provided on the table side with the engaging hole formed on the pallet side. Also, by means such as T-groove, the pallet does not drop even if the table is tilted. Further, when machining is performed with the pallet in a horizontal state, the pressure of the pallet clamp hydraulic power source may drop, and an accident may occur in which the pallet floats.

[0003]

[Problems to be solved by the device]

 By the way, as described above, in the pin insertion connection and the connection using the T-groove, it is necessary to perform special processing suitable for the pallet. The present invention uses a standard pallet without any special processing on the pallet, and the locking mechanism prevents the pallet from dropping or rising even if the pressure of the hydraulic source for the pallet clamp decreases. It is intended to obtain a pallet kunamp device equipped with.

[0004]

[Means for Solving the Problems]

 According to the present invention, when the piston with the collet for fixing the pull stud mounted on the pallet is clamped, another piston that locks the piston with the collet so that the piston with the collet does not displace is activated when the hydraulic pressure decreases. The configuration is as follows.

In a pallet clamp device configured to move a clamp piston connected to a gripping member by fluid pressure to clamp a pallet, a fluid circuit connected to the same fluid pressure source as that for operating the clamp piston. A lock piston that is displaced against the spring is provided via a lock pin that is connected to the movement of the lock piston and that moves forward and backward is arranged between the clamp piston and the lock piston to reduce the oil pressure. The pallet clamp device is configured so that the spring force causes the lock piston to rise, and accordingly, the lock pin engages with the side surface of the clamp piston to prevent displacement of the clamp piston. In the pallet fixing device configured to move the piston connected to the gripping member by hydraulic pressure to lock the pallet, the pallet fixing device is displaced against the spring through the hydraulic circuit connected to the same hydraulic circuit. When the hydraulic pressure decreases, the piston rises due to the spring force when the hydraulic pressure decreases, and the moving body engages with the pallet fixed piston side face, and the pallet A pallet clamp device for a tilting table configured to prevent displacement of the gripping piston.

[0006]

[Action]

 According to the present invention, the collet piston for pulling and fixing the pull stud provided on the lower surface of the pallet to the table side reduces the hydraulic pressure of the hydraulic source during operation by hydraulic pressure via the check valve from the hydraulic source. Even if there is, the lock pin that prevents the displacement due to the decrease in hydraulic pressure of the collet-equipped piston before engaging with the collet-equipped piston engages the collet-equipped piston and prevents the displacement. , The pallet is held and fixed on the table continuously.

[0007]

【Example】

 FIG. 1 is a vertical sectional view showing the structure of a pallet clamp device according to the present invention, and FIG. 2 is an explanatory view showing the overall structure of the pallet clamp device. As shown in FIG. 2, the pallet 1 is attached to the table 4 by a pallet clamp device 3 which is clamped by a hydraulic circuit 2. Here, reference symbol P is a pump which is a hydraulic pressure source, and T is a tank.

As shown in FIG. 1, a pull stud 5 is planted on the lower surface of the pallet 1, and a positioning bush 6 centered on the pull stud 5 is screwed and fixed. A pallet clamp device 3 is provided on the table 4 at a position facing the pull stud 5 planted in the pallet 1. The pallet clamp device 3 is a cylinder for gripping and pulling and fixing the pull stud 5. It is composed of a mechanism A and a lock cylinder mechanism B for preventing the crumpling force from disappearing when the hydraulic pressure decreases.

Next, the cylinder mechanism A for gripping and pulling and fixing the pull stud 5 will be described. When the pallet 1 is clamped on the table 4, a piston 7 with a collet for gripping and pulling and fixing the pull stud 5 is held at a position on the upper surface of the table 4 facing the pull stud 5 provided on the lower surface of the pallet 1. The inside of the cylinder 9 of the cylinder member 8 of the clamp device 3 is provided so as to be movable up and down by hydraulic pressure, and the upper end of the collet-attached piston 7 is a ball type collet portion 10 having a ball 7a. That is, a cylinder 9 on which the piston 7 with collet slides up and down is formed on the lower side of the cylinder member 8, and a cylinder hole 9a on which the cylinder shaft 7b of the piston 7 with collet slides is formed on the upper side thereof. A conduit 11 is connected to the cylinder 9 by a hydraulic circuit including a check valve.

The upper part of the cylinder shaft 7b of the colleted piston 7 is a hollow shaft, and a cap-shaped body 13 biased upward by a built-in spring 12 is provided inside the cylinder shaft 7b. A ball 7a that engages with the enlarged head portion 5a of the pull stud 5 on the lower surface is fitted. This ball 7a acts as a so-called ball type collet chuck, and is retracted outward by an annular recess 15 formed on the inner diameter surface of a positioning cone bush 14 that fits over the piston shaft 7b protruding from the upper surface of the cylinder member 8. , Is configured to release the collet action. The positioning cone bush 14 is fixed to the cylinder member 8 with a mounting screw. When the pallet 1 is mounted on the table 4, the positioning cone bush 14 is engaged with the positioning bush 6 of the pallet to engage the table with the pallet. When the pull stud 5 is inserted into the collet hollow shaft, the ball 7a of the piston 7 with collet is located at the annular recess 15 position of the positioning cone bush 14, so that the ball 7a retracts into the annular recess 15. The pull stud 5 is inserted into the collet part 10 of the collet-equipped piston 7. Since the cap-shaped body 13 is biased upward by the internal spring 12, the cap-shaped body 13 stops moving up to the position of the ball 7a when the pull stud 5 is not inserted, so that the ball 7a does not drop into the hollow shaft. To prevent.

To prevent the clamping force for holding the pull stud 5 of the pallet 1 from disappearing when the hydraulic pressure drops when the pump P stops driving due to power failure or failure during an emergency stop. The lock cylinder mechanism B is provided in parallel with the cylinder mechanism A as shown in FIG. That is, a small diameter cylinder 15 is provided adjacent to the cylinder 9 of the colleted piston 7, and a through hole 16 is formed between the cylinder 9 and the cylinder 15. The through hole 16 has a colleted hole. A lock pin 17 that engages with an annular V-shaped recess 7c provided on the peripheral wall of the piston 7 to prevent its displacement is slidably engaged. The lock pin 17 has a small-diameter peripheral wall portion 18a formed on the upper side. It can be displaced by sliding the piston 18 up and down. The vertical movement of the piston 18 is lowered by hydraulic pressure from a conduit 19 which is directly connected to a pump P which is connected to an upper portion of the cylinder 15, and is operated so as to be raised by a spring 20 provided at a lower portion of the piston. When it is lowered, as shown in the figure, the piston 18 rises, the lock pin 17 is pushed leftward by the side wall of the piston 18, and the pull stud 5 is gripped and pulled. Its tip engages with the recess 7c. When hydraulic pressure is applied to the conduit 19, the piston 18 descends, and the rear end of the lock pin 17 can be retracted into the piston small diameter peripheral wall portion 18a, so that the displacement of the colleted piston 7 is not hindered. A ball 17a is provided at the rear end of the lock pin 17 so that the lock pin 17 can be smoothly moved by the displacement of the piston 18.

Since the pallet clamp device 3 according to the present invention is configured as described above, the pump P is stopped while the piston 7 with collet in the cylinder mechanism A holds and pulls the pull stud 5 of the pallet 1. When the hydraulic pressure in the hydraulic circuit decreases, the hydraulic pressure in the hydraulic conduit 19 from the pump P rapidly decreases, the piston 18 of the lock cylinder mechanism B rises due to the action of the spring 20, and the lock pin 17 with the collet is attached. By engaging with the piston 7, the pull stud 5 of the pallet 1 is maintained in the gripped state. At this time, even if a force to pull up the colleted piston 7 is applied, the lock pin 17 is mechanically and reliably blocked by the side wall of the piston 18 via the ball 17a, and the pallet does not fall off. Absolutely impossible.

[0013]

[Effect of the device]

 According to the present invention, even when the colleted piston 7 grips and pulls the pull stud 5 of the pallet 1 and an emergency occurs, the pump P is stopped and the hydraulic pressure in the hydraulic circuit is reduced. The attached piston 7 is connected to the hydraulic circuit via a check valve, while the lock cylinder mechanism B is supplied with hydraulic pressure from a conduit directly connected to the pump P, and therefore the lock cylinder mechanism B is supplied from the cylinder mechanism A. The hydraulic pressure rapidly drops, and the piston 18 that operates the lock pin 17 immediately rises by the force of the spring 20 and engages the lock pin 17 with the collet-equipped piston 7, so that the pull stud 5 is securely gripped. The traction can be maintained continuously, and there is no fear that the pallet will fall off, drop, or float even when the table 4 is tilted or is being processed.

Further, according to the present invention, it is not necessary to provide the pallet with a special processing such as a pin coupling hole or a T-groove for preventing the pallet from coming off or dropping from the table, and the pallet locks the standard pallet. The device is obtained. As described above, when a large amount of pallets are used in a processing system or the like, there is no need to perform additional processing on the pallet, which is very effective in reducing costs.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment according to the present invention.

FIG. 2 is an explanatory diagram showing the overall configuration of a pallet clamp device.

[Explanation of symbols]

 1 Pallet 2 Hydraulic circuit 3 Pallet clamp device 4 Table 5 Pull stud 6 Positioning bush 7 Collet piston 7a Ball 7b Piston shaft 7c Annular V-shaped recess 8 Cylinder member 9 Cylinder 10 Collet part 11 Conduit 12 Spring 13 Cap-shaped body 14 Positioning cone Bush 15 Annular recess 16 Through hole 17 Lock pin 18 Piston 19 Conduit 20 Spring A Cylinder mechanism B Lock cylinder mechanism

Claims (1)

[Scope of utility model registration request] 1. A pallet clamp device configured to clamp a pallet by moving a clamp piston connected to a gripping member by fluid pressure, and a fluid connected to the same fluid pressure source as that for operating the clamp piston. A lock piston, which is displaced against a spring through a circuit, is provided, and a lock pin that moves forward and backward in connection with the movement of the lock piston is arranged between the clamp piston and the lock piston to reduce the hydraulic pressure. At this time, the spring force causes the lock piston to rise, and accordingly, the lock pin engages with the side surface of the clamp piston to prevent displacement of the clamp piston.